How to bind a Store using Spring Cloud Stream and Kafka? - spring-cloud-stream-binder-kafka

I'd like to use a Kafka state store of type KeyValueStore in a sample application using the Kafka Binder of Spring Cloud Stream.
According to the documentation, it should be pretty simple.
This is my main class:
#SpringBootApplication
public class KafkaStreamTestApplication {
public static void main(String[] args) {
SpringApplication.run(KafkaStreamTestApplication.class, args);
}
#Bean
public BiFunction<KStream<String, String>, KeyValueStore<String,String>, KStream<String, String>> process(){
return (input,store) -> input.mapValues(v -> v.toUpperCase());
}
#Bean
public StoreBuilder myStore() {
return Stores.keyValueStoreBuilder(
Stores.persistentKeyValueStore("my-store"), Serdes.String(),
Serdes.String());
}
}
I suppose that the KeyValueStore should be passed as the second parameter of the "process" method, but the application fails to start with the message below:
Caused by: java.lang.IllegalStateException: No factory found for binding target type: org.apache.kafka.streams.state.KeyValueStore among registered factories: channelFactory,messageSourceFactory,kStreamBoundElementFactory,kTableBoundElementFactory,globalKTableBoundElementFactory
at org.springframework.cloud.stream.binding.AbstractBindableProxyFactory.getBindingTargetFactory(AbstractBindableProxyFactory.java:82) ~[spring-cloud-stream-3.0.3.RELEASE.jar:3.0.3.RELEASE]
at org.springframework.cloud.stream.binder.kafka.streams.function.KafkaStreamsBindableProxyFactory.bindInput(KafkaStreamsBindableProxyFactory.java:191) ~[spring-cloud-stream-binder-kafka-streams-3.0.3.RELEASE.jar:3.0.3.RELEASE]
at org.springframework.cloud.stream.binder.kafka.streams.function.KafkaStreamsBindableProxyFactory.afterPropertiesSet(KafkaStreamsBindableProxyFactory.java:103) ~[spring-cloud-stream-binder-kafka-streams-3.0.3.RELEASE.jar:3.0.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792) ~[spring-beans-5.2.5.RELEASE.jar:5.2.5.RELEASE]

I found the solution about how to use a store reading an unit test in Spring Cloud Stream.
The code below is how I applied that solution to my code.
The transformer uses the Store provided by Spring bean method "myStore"
#SpringBootApplication
public class KafkaStreamTestApplication {
public static final String MY_STORE_NAME = "my-store";
public static void main(String[] args) {
SpringApplication.run(KafkaStreamTestApplication.class, args);
}
#Bean
public Function<KStream<String, String>, KStream<String, String>> process2(){
return (input) -> input.
transformValues(() -> new MyValueTransformer(), MY_STORE_NAME);
}
#Bean
public StoreBuilder<?> myStore() {
return Stores.keyValueStoreBuilder(
Stores.persistentKeyValueStore(MY_STORE_NAME), Serdes.String(),
Serdes.String());
}
}
public class MyValueTransformer implements ValueTransformer<String, String> {
private KeyValueStore<String,String> store;
private ProcessorContext context;
#Override
public void init(ProcessorContext context) {
this.context = context;
store = (KeyValueStore<String, String>) this.context.getStateStore(KafkaStreamTestApplication.MY_STORE_NAME);
}
#Override
public String transform(String value) {
String tValue = store.get(value);
if(tValue==null) {
store.put(value, value.toUpperCase());
}
return tValue;
}
#Override
public void close() {
if(store!=null) {
store.close();
}
}
}

Related

processing strategy of message in spring kafka listener

Just wanted to make sure that whether messages are processed in correct way or not. When the message gets received at listener, it will be always processed by a new thread( defined the processor bean as prototype). is this implementation correct ? (i have Considered the listener is not thread safe, so for this reason the prototype scope of bean to process the message has been used)
(Input : TestTopic- 5 partitions - 1 consumer) or (Input : TestTopic- 5 partitions - 5 consumers)
public class EventListener {
#Autowired
private EventProcessor eventProcessor;
#KafkaListener(topics = "TestTopic", containerFactory = "kafkaListenerContainerFactory",
autoStartup = "true")
public void onMessage(
#Payload List<ConsumerRecord<String, String>> consumerRecords, Acknowledgment acknowledgment) {
eventProcessor.processAndAcknowledgeBatchMessages(consumerRecords, acknowledgment);
}
}
//event processor
#Slf4j
#Component
#Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
#NoArgsConstructor
#SuppressWarnings("unused")
public class EventProcessorImpl implements EventProcessor {
#Autowired
private KafkaProducerTemplate kafkaProducerTemplate;
#Autowired
private ObjectMapper localObjectMapper;
#Autowired
private Dao dao;
public void processAndAcknowledgeBatchMessages(
List<ConsumerRecord<String, String>> consumerRecords, Acknowledgment acknowledgment) {
long start = System.currentTimeMillis();
consumerRecords.forEach( consumerRecord -> {
Event event = localObjectMapper.readValue(consumerRecord.value(), Event.class);
dao.save(process(event));
});
acknowledgment.acknowledge();
}
}
No it is not correct; you should not execute on another thread; it will cause problems with committing offsets and error handling.
Also, making the EventProcessorImpl a prototype bean won't help. That just means a new instance is used each time the bean is referenced.
Since it is #Autowired it is only referenced once, during initialization. To get a new instance for each request, you would need to call getBean() on the application context each time.
It is better to make your code thread-safe.
EDIT
There are (at least) a couple of ways to deal with a not thread-safe service defined in prototype scope.
Use a ThreadLocal:
#SpringBootApplication
public class So68447863Application {
public static void main(String[] args) {
SpringApplication.run(So68447863Application.class, args);
}
private static final ThreadLocal<NotThreadSafeService> SERVICES = new ThreadLocal<>();
#Autowired
ApplicationContext context;
#KafkaListener(id = "so68447863", topics = "so68447863", concurrency = "5")
void listen(String in) {
NotThreadSafeService service = SERVICES.get();
if (service == null) {
service = this.context.getBean(NotThreadSafeService.class);
SERVICES.set(service);
}
service.process(in);
}
#EventListener
void removeService(ConsumerStoppedEvent event) {
System.out.println("Consumer stopped; removing TL");
SERVICES.remove();
}
#Bean
NewTopic topic() {
return TopicBuilder.name("so68447863").partitions(10).replicas(1).build();
}
#Bean
#Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
NotThreadSafeService service() {
return new NotThreadSafeService();
}
}
class NotThreadSafeService {
void process(String msg) {
System.out.println(msg + " processed by " + this);
}
}
Use a pool of instances.
#SpringBootApplication
public class So68447863Application {
public static void main(String[] args) {
SpringApplication.run(So68447863Application.class, args);
}
private static final BlockingQueue<NotThreadSafeService> SERVICES = new LinkedBlockingQueue<>();
#Autowired
ApplicationContext context;
#KafkaListener(id = "so68447863", topics = "so68447863", concurrency = "5")
void listen(String in) {
NotThreadSafeService service = SERVICES.poll();
if (service == null) {
service = this.context.getBean(NotThreadSafeService.class);
}
try {
service.process(in);
}
finally {
SERVICES.add(service);
}
}
#Bean
NewTopic topic() {
return TopicBuilder.name("so68447863").partitions(10).replicas(1).build();
}
#Bean
#Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
NotThreadSafeService service() {
return new NotThreadSafeService();
}
}
class NotThreadSafeService {
void process(String msg) {
System.out.println(msg + " processed by " + this);
}
}

SeekToCurrentErrorHandler: DeadLetterPublishingRecoverer is not handling deserialize errors

I am trying to write kafka consumer using spring-kafka version 2.3.0.M2 library.
To handle run time errors I am using SeekToCurrentErrorHandler.class with DeadLetterPublishingRecoverer as my recoverer. This works fine only when my consumer code throws exception, but fails when unable to deserialize the message.
I tried implementing ErrorHandler myself and I was successful but with this approach I myself end up writing DLT code to handle error messages which I do not want to do.
Below are my kafka properties
spring:
kafka:
consumer:
bootstrap-servers: localhost:9092
group-id: group_id
auto-offset-reset: latest
key-deserializer: org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
value-deserializer: org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
properties:
spring.json.trusted.packages: com.mypackage
spring.deserializer.key.delegate.class: org.apache.kafka.common.serialization.StringDeserializer
spring.deserializer.value.delegate.class: org.apache.kafka.common.serialization.StringDeserializer
public ConcurrentKafkaListenerContainerFactory kafkaListenerContainerFactory(
ConcurrentKafkaListenerContainerFactoryConfigurer configurer,
ConsumerFactory<Object, Object> kafkaConsumerFactory,
KafkaTemplate<Object, Object> template) {
ConcurrentKafkaListenerContainerFactory<Object, Object> factory = new ConcurrentKafkaListenerContainerFactory<>();
configurer.configure(factory, kafkaConsumerFactory);
factory.setErrorHandler(new SeekToCurrentErrorHandler(new DeadLetterPublishingRecoverer(template), maxFailures));}
It works fine for me (note that Boot will auto-configure the error handler)...
#SpringBootApplication
public class So56728833Application {
public static void main(String[] args) {
SpringApplication.run(So56728833Application.class, args);
}
#Bean
public SeekToCurrentErrorHandler errorHandler(KafkaTemplate<String, String> template) {
SeekToCurrentErrorHandler eh = new SeekToCurrentErrorHandler(new DeadLetterPublishingRecoverer(template), 3);
eh.setClassifier( // retry for all except deserialization exceptions
new BinaryExceptionClassifier(Collections.singletonList(DeserializationException.class), false));
return eh;
}
#KafkaListener(id = "so56728833"
+ "", topics = "so56728833")
public void listen(Foo in) {
System.out.println(in);
if (in.getBar().equals("baz")) {
throw new IllegalStateException("Test retries");
}
}
#KafkaListener(id = "so56728833dlt", topics = "so56728833.DLT")
public void listenDLT(Object in) {
System.out.println("Received from DLT: " + (in instanceof byte[] ? new String((byte[]) in) : in));
}
#Bean
public NewTopic topic() {
return TopicBuilder.name("so56728833").partitions(1).replicas(1).build();
}
#Bean
public NewTopic dlt() {
return TopicBuilder.name("so56728833.DLT").partitions(1).replicas(1).build();
}
public static class Foo {
private String bar;
public Foo() {
super();
}
public Foo(String bar) {
this.bar = bar;
}
public String getBar() {
return this.bar;
}
public void setBar(String bar) {
this.bar = bar;
}
#Override
public String toString() {
return "Foo [bar=" + this.bar + "]";
}
}
}
spring:
kafka:
consumer:
auto-offset-reset: earliest
enable-auto-commit: false
key-deserializer: org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
value-deserializer: org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
properties:
spring.json.trusted.packages: com.example
spring.deserializer.key.delegate.class: org.springframework.kafka.support.serializer.JsonDeserializer
spring.deserializer.value.delegate.class: org.springframework.kafka.support.serializer.JsonDeserializer
spring.json.value.default.type: com.example.So56728833Application$Foo
producer:
key-serializer: org.springframework.kafka.support.serializer.JsonSerializer
value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
logging:
level:
org.springframework.kafka: trace
I have 3 records in the topic:
"badJSON"
"{\"bar\":\"baz\"}"
"{\"bar\":\"qux\"}"
I see the first one going directly to the DLT, and the second one goes there after 3 attempts.

Data fetching from database on each hit not from the cache

This is the Application.java class
#Configuration
#SpringBootApplication
//#EnableGlobalMethodSecurity(prePostEnabled=true)
#EnableTransactionManagement
#EnableCaching
#EnableJpaRepositories(basePackages="om.gov.moh.irs.dao.repos",repositoryImplementationPostfix="CustomImpl")
public class Application extends SpringBootServletInitializer {
#Autowired
Environment env;
#Bean
#ConfigurationProperties("spring.datasource")
public ComboPooledDataSource dataSource() {
return new ComboPooledDataSource();
}
#Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(Application.class);
}
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Bean
public ResourceBundleMessageSource messageSource() {
ResourceBundleMessageSource source = new ResourceBundleMessageSource();
source.setBasenames("messages"); // name of the resource bundle
source.setUseCodeAsDefaultMessage(true);
return source;
}
#Bean
MultipartConfigElement multipartConfigElement() {
MultipartConfigFactory factory = new MultipartConfigFactory();
factory.setMaxFileSize(env.getProperty("multipart.maxFileSize"));
factory.setMaxRequestSize(env.getProperty("multipart.maxRequestSize"));
return factory.createMultipartConfig();
}
}
This is the dto class which Im trying to cache.
public class PaginationDto implements Serializable {
private static final long serialVersionUID = 1L;
public Integer totalRecords;
public List<?> paginatedList;
//constructor and getter setter here
}
Controller class
#RequestMapping(value="categories", method=RequestMethod.POST, produces = { "application/json" })
public #ResponseBody ResultDecorator searchCategories(#RequestBody CategoryDto categoryDto) int pageSize, #RequestParam("sort") String sortOrder) throws BusinessException{
return handler.resolveResult(categoryService.searchCategory(categoryDto), OperationEnum.SEARCH);
}
Service class where #cacheable is defined.
#Override
#Cacheable("category")
public PaginationDto searchCategory(CategoryDto categoryDto) throws CategoryException {
System.out.println("#######category");
PaginationDto paginationDtoResponse = null;
paginationDtoResponse = categoryRepoCustom.fetchCategories(categoryDto);
return paginationDtoResponse;
}
Defined ehcache.xml file
<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://www.ehcache.org/ehcache.xsd"
updateCheck="true" monitoring="autodetect" dynamicConfig="true">
<cache name="category"
maxElementsInMemory="100" eternal="false"
overflowToDisk="false"
timeToLiveSeconds="30000" timeToIdleSeconds="0"
memoryStoreEvictionPolicy="LFU" transactionalMode="off">
</cache>
</ehcache>
On hitting this http://localhost:9190/isa/categories each time console log is printing, which means data is not fetching from the cache.

#Context WebConfig not injected when using JerseyTest 2.0

I have a simple resource like:
#Path("/")
public class RootResource {
#Context WebConfig wc;
#PostConstruct
public void init() {
assertNotNull(wc);
}
#GET
public void String method() {
return "Hello\n";
}
}
Which I am trying to use with JerseyTest (2.x, not 1.x) and the GrizzlyTestContainerFactory.
I can't work out what I need to do in terms of config to get the WebConfig object injected.
I solved this issue by creating a subclass of GrizzlyTestContainerFactory and explicitly loading the Jersey servlet. This triggers the injection of the WebConfig object. The code looks like this:
public class ExtendedGrizzlyTestContainerFactory implements TestContainerFactory {
private static class GrizzlyTestContainer implements TestContainer {
private final URI uri;
private final ApplicationHandler appHandler;
private HttpServer server;
private static final Logger LOGGER = Logger.getLogger(GrizzlyTestContainer.class.getName());
private GrizzlyTestContainer(URI uri, ApplicationHandler appHandler) {
this.appHandler = appHandler;
this.uri = uri;
}
#Override
public ClientConfig getClientConfig() {
return null;
}
#Override
public URI getBaseUri() {
return uri;
}
#Override
public void start() {
if (LOGGER.isLoggable(Level.INFO)) {
LOGGER.log(Level.INFO, "Starting GrizzlyTestContainer...");
}
try {
this.server = GrizzlyHttpServerFactory.createHttpServer(uri, appHandler);
// Initialize and register Jersey Servlet
WebappContext context = new WebappContext("WebappContext", "");
ServletRegistration registration = context.addServlet("ServletContainer", ServletContainer.class);
registration.setInitParameter("javax.ws.rs.Application",
appHandler.getConfiguration().getApplication().getClass().getName());
// Add an init parameter - this could be loaded from a parameter in the constructor
registration.setInitParameter("myparam", "myvalue");
registration.addMapping("/*");
context.deploy(server);
} catch (ProcessingException e) {
throw new TestContainerException(e);
}
}
#Override
public void stop() {
if (LOGGER.isLoggable(Level.INFO)) {
LOGGER.log(Level.INFO, "Stopping GrizzlyTestContainer...");
}
this.server.stop();
}
}
#Override
public TestContainer create(URI baseUri, ApplicationHandler application) throws IllegalArgumentException {
return new GrizzlyTestContainer(baseUri, application);
}
Notice that the Jersey Servlet configuration is being loaded from the ApplicationHandler that is passed in as a parameter using the inner Application object's class name (ResourceConfig is a subclass of Application). Therefore, you also need to create a subclass of ResourceConfig for this approach to work. The code for this is very simple:
package com.example;
import org.glassfish.jersey.server.ResourceConfig;
public class MyResourceConfig extends ResourceConfig {
public MyResourceConfig() {
super(MyResource.class);
}
}
This assumes the resource you are testing is MyResource. You also need to override a couple of methods in your test like this:
public class MyResourceTest extends JerseyTest {
public MyResourceTest() throws TestContainerException {
}
#Override
protected Application configure() {
return new MyResourceConfig();
}
#Override
protected TestContainerFactory getTestContainerFactory() throws TestContainerException {
return new ExtendedGrizzlyTestContainerFactory();
}
#Test
public void testCreateSimpleBean() {
final String beanList = target("test").request().get(String.class);
Assert.assertNotNull(beanList);
}
}
Finally, for completeness, here is the code for MyResource:
#Path("test")
public class MyResource {
#Context WebConfig wc;
#PostConstruct
public void init() {
System.out.println("WebConfig: " + wc);
String url = wc.getInitParameter("myparam");
System.out.println("myparam = "+url);
}
#GET
#Produces(MediaType.APPLICATION_JSON)
public Collection<TestBean> createSimpleBean() {
Collection<TestBean> res = new ArrayList<TestBean>();
res.add(new TestBean("a", 1, 1L));
res.add(new TestBean("b", 2, 2L));
return res;
}
#POST
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public TestBean roundTrip(TestBean s) {
return s;
}
}
The output of running the test shows that the WebConfig is loaded and the init param is now available:
WebConfig: org.glassfish.jersey.servlet.WebServletConfig#107d0f44
myparam = myvalue
The solution from #ametke worked well but wasn't picking up my ExceptionMapper classes. To solve this I simplified the start() method to:
#Override
public void start() {
try {
initParams.put("jersey.config.server.provider.packages", "my.resources;my.config");
this.server = GrizzlyWebContainerFactory.create(uri, initParams);
} catch (ProcessingException | IOException e) {
throw new TestContainerException(e);
}
}
This was based on Problems running JerseyTest when dealing with HttpServletResponse

Spring MVC doesn't handle the error came from hibernate validator

I create form and controller this form have some validation constrains using Hibernate validator. I face problem when starting test the validation constrains but I got Blue Exception page with the attributemodel with the rejected.
This the configuration
#Configuration
#ComponentScan(basePackages = {"com.whatever.core.web"})
#EnableWebMvc
public class WebMvcConfig extends WebMvcConfigurationSupport {
private static final String MESSAGE_SOURCE = "/WEB-INF/classes/messages";
private static final String TILES = "/WEB-INF/tiles/tiles.xml";
private static final String VIEWS = "/WEB-INF/views/**/views.xml";
private static final String RESOURCES_HANDLER = "/resources/";
private static final String RESOURCES_LOCATION = RESOURCES_HANDLER + "**";
#Override
public RequestMappingHandlerMapping requestMappingHandlerMapping() {
RequestMappingHandlerMapping requestMappingHandlerMapping = super.requestMappingHandlerMapping();
requestMappingHandlerMapping.setUseSuffixPatternMatch(false);
requestMappingHandlerMapping.setUseTrailingSlashMatch(false);
return requestMappingHandlerMapping;
}
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(new MappingJacksonHttpMessageConverter());
}
#Bean(name = "messageSource")
public MessageSource configureMessageSource() {
ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
messageSource.setBasename(MESSAGE_SOURCE);
messageSource.setCacheSeconds(5);
return messageSource;
}
#Bean
public TilesViewResolver configureTilesViewResolver() {
return new TilesViewResolver();
}
#Bean
public TilesConfigurer configureTilesConfigurer() {
TilesConfigurer configurer = new TilesConfigurer();
configurer.setDefinitions(new String[] {TILES, VIEWS});
return configurer;
}
#Override
public Validator getValidator() {
LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
validator.setValidationMessageSource(configureMessageSource());
return validator;
}
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler(RESOURCES_HANDLER).addResourceLocations(RESOURCES_LOCATION);
}
#Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
configurer.enable();
}
}
and the controller here
if(result.hasErrors()){
return null; OR "view name"
}
User user = new User();
user.setUsername(userModel.getUsername());
user.setFirstName(userModel.getFirstName());
user.setLastName(userModel.getLastName());
user.setGender(userModel.getGender());
user.setLocation(userModel.getLocation());
user.setPassword(passwordEncoder.encodePassword(userModel.getPassword(),null));
userRepository.save(user);
doAutoLogin(userModel.getUsername(),userModel.getPassword(),request);
return "redirect:/home";
NOTE: I use springMVC, spring security, tiles, and hibernate validator
I used SpringMVC with hibernate validator with XML configuration and portal environment and work fine I don't know what the wrong here!!
I Found the issue! the signature of the method controller should be like this
public String signup(#ModelAttribute("userModel") #Valid SignupForm userModel,BindingResult result,HttpServletRequest request,HttpServletResponse response,ModelMap model)
as what I read in sprinsource forum, the BindingResult should follow the modelAttribute and work find. I didn't find any official documentation for this but its work now.
to see the thread of springsource forum check this link http://forum.springsource.org/showthread.php?85815-BindException-Thrown-on-bind-errors-(instead-of-returning-errors-to-controller-method

Resources